1. Field of the Invention
The present invention relates to a refrigerant evaporator used in a refrigeration cycle such as of a car air-conditioner or room air-conditioner.
2. Description of the Related Art
In a refrigerant evaporator of a refrigeration cycle, the amount of the refrigerant distributed to each of a plurality of tubes constituting parallel refrigerant passageways is desirably homogeneous so as to improve the efficiency thereof.
Therefore, Japanese Examined Patent Publication (Kokoku) No. 2-63146 discloses a technique in which a liquid refrigerant condensed in a refrigerant condenser is further supercooled and then reduced in pressure by an expansion valve, then the degree of dryness of the refrigerant flowing into a flow divider is reduced to be as small as possible so as to make the amount of distribution of refrigerant from the flow divider to the respective refrigerant passageways of the refrigerant evaporator uniform.
Also, Japanese Unexamined Patent Publication (Kokai) No. 61-62756 discloses a technique in which after the supercooled liquid refrigerant is reduced in pressure, a refrigerant which is still in a liquid single-phase state is introduced to the flow divider so as to make the amount of distribution of refrigerant to the respective refrigerant passageways uniform.
According to the above-mentioned related art, however, there were problems in that a supercooler for further supercooling the refrigerant condensed by the refrigerant condenser became necessary, and major modification of the refrigeration cycle became required since a two-stage pressure reduction system was adopted, etc, whereby the system became complex and the costs rose.